Development of a Real-Time Pixel Array-Type Detector for Ultrahigh Dose-Rate Beams.

Although research into ultrahigh dose-rate (UHDR) radiation therapy is ongoing, there is a significant lack of experimental measurements for two-dimensional (2D) dose-rate distributions. Additionally, conventional pixel-type detectors result in significant beam loss. In this study, we developed a pixel array-type detector with adjustable gaps and a data acquisition system to evaluate its effectiveness in measuring UHDR proton beams in real time. We measured a UHDR beam at the Korea Institute of Radiological and Medical Sciences using an MC-50 cyclotron, which produced a 45-MeV energy beam with a current range of 10-70 nA, to confirm the UHDR beam conditions. To minimize beam loss during measurement, we adjusted the gap and high voltage on the detector and determined the collection efficiency of the developed detector through Monte Carlo simulation and experimental measurements of the 2D dose-rate distribution. We also verified the accuracy of the real-time position measurement using the developed detector with a 226.29-MeV PBS beam at the National Cancer Center of the Republic of Korea. Our results indicate that, for a current of 70 nA with an energy beam of 45 MeV generated using the MC-50 cyclotron, the dose rate exceeded 300 Gy/s at the center of the beam, indicating UHDR conditions. Simulation and experimental measurements show that fixing the gap at 2 mm and the high voltage at 1000 V resulted in a less than 1% loss of collection efficiency when measuring UHDR beams. Furthermore, we achieved real-time measurements of the beam position with an accuracy of within 2% at five reference points. In conclusion, our study developed a beam monitoring system that can measure UHDR proton beams and confirmed the accuracy of the beam position and profile through real-time data transmission.

Numerical and Experimental Analysis of DVA on the Flexible-Rigid Rail Vehicle Carbody Resonant Vibration.

This paper examines the influence of the equipment considered as a DVA (Dynamic Vibration Absorber) upon the mode of vertical vibrations of the car body in high-speed vehicles. The car body is represented as an Euler-Bernoulli beam to minimize flexible vibration. The DVA approach is used to find the appropriate suspension frequencies for various types of equipment. A vertical mathematical model with a flexible car body and equipment is developed to investigate the effect of equipment mass, suspension stiffness, damping, and mounting location on car-body flexible vibrations. A three-dimensional, rigid-flexible coupled vehicle system dynamics model is developed to simulate the car body and equipment's response to track irregularities. The experimental result was considered to verify the theoretical analysis and dynamic simulation. The mathematical analysis demonstrates that the DVA theory can be used to design the suspension parameters of the equipment and that it is suitable and effective in reducing the flexible vibration of the car body in which the vertical bending mode is greatly affected. Heavy equipment should be mounted as close to the car body's center as possible to achieve significant flexible vibration reduction, whereas light equipment contributes very little flexible vibration reduction.

Oncologic Outcome and Morbidity in the Elderly Rectal Cancer Patients After Preoperative Chemoradiotherapy and Total Mesorectal Excision: A Multi-institutional and Case-matched Control Study.

OBJECTIVE: To determine the toxicity and oncologic outcome of neoadjuvant chemoradiotherapy (CRT) followed by curative total mesorectal excision (TME) in the elderly (≥70 yrs) and younger (<70 yrs) rectal cancer patients. BACKGROUND: Sufficient data for elderly rectal cancer patients who received definitive trimodality have not been accumulated yet. PATIENTS AND METHODS: A total of 1232 rectal cancer patients who received neoadjuvant CRT and TME were enrolled in this study. After propensity-score matching, 310 younger patients and 310 elderly patients were matched with 1:1 manner. Treatment response, toxicity, surgical outcome, recurrence, and survival were assessed and compared between the 2 groups of patients. RESULTS: The median age was 58 years for the younger patient group and 74 years for the elderly group. Pathologic complete response rates were not significantly different between the 2 groups (younger and elderly: 17.1% vs 14.8%, P = 0.443). The 5-year recurrence-free survival (younger and elderly: 67.7% vs 65.5%, P = 0.483) and overall survival (younger and elderly: 82.9% vs. 79.5%, P = 0.271) rates were not significantly different between the 2 groups either. Adjuvant chemotherapy after surgery was less frequently delivered to the elderly than that to younger patients (83.9% vs 69.0%). Grade 3 or higher acute hematologic toxicity was observed more frequently in the elderly than that in the younger group (9.0% vs 16.1%, P = 0.008). Late complication rate was higher in the elderly group compared with that in the younger group without statistical significance (2.6% vs 4.5%, P = 0.193). CONCLUSIONS: Although acute hematologic toxicity was observed more frequently in the elderly patients than that in the younger patients, elderly rectal cancer patients with good performance status who received preoperative CRT and TME showed favorable tumor response and recurrence-free survival similar to younger patients.

Nadir/pre-chemoradiotherapy ratio of white blood-cell count can predict tumor response and recurrence-free survival in locally advanced rectal cancer: a multi-institutional analysis.

PURPOSE: The objective of this study was to evaluate whether change of white blood-cell (WBC) count before and during chemoradiotherapy (CRT) might be associated with susceptibility to radiation and tumor response. METHODS: Medical records of 641 patients with rectal cancer who received preoperative CRT followed by curative surgery were retrospectively reviewed in five tertiary centers. Complete blood cell with differential count was measured weekly during the period of CRT. We assessed nadir/pre-CRT ratio of WBC count as a predictor for tumor response to CRT and a prognostic factor for recurrence-free survival. RESULTS: Enrolled patients were divided into low WBC ratio (LWR) and high WBC ratio (HWR) arms with cut-off value of 0.49 calculated by receiver operating characteristic curve. Of 641 patients, 490 (76.4%) and 151 (23.6%) were categorized into HWR (> 0.49) arm and LWR (≤ 0.49) arms, respectively. Complete pathologic response rate after CRT was significantly higher in LWR arm than that in HWR arm (23.8% vs. 12.2%, p = 0.001). In logistic regression analysis, carcinoembryonic antigen (CEA) level over 5 ng/ml [adjusted odds ratio (OR) 0.566, 95% confidence interval (CI) 0.351-0.912; p = 0.019) and HWR (adjusted OR 0.412, 95% CI 0.256-0.663; p = 0.001) were significantly negative factors of pathologic complete response. The 5-year recurrence-free survival rate was significantly higher in the LWR group than that in the HWR group (83.3% vs. 67.6%, p = 0.001). CONCLUSION: Low nadir/pre-chemoradiotherapy ratio during preoperative CRT can predict good tumor response. It is significantly associated with improved recurrence-free survival in rectal cancer.

Surface-Colour Characteristics and Flow of Carbon Aminosilica Black Paste Using a Redispersible Polymer.

The surface colour of exposed concrete is one of the most obvious characteristics of quality because it is the first one to be seen. However, efflorescence generally changes the colour impression of the material surface and of the concrete facade as a whole. This study investigated the efflorescence of carbon aminosilica black (CASB) mortar and the effect of redispersible polymer powder (RPP) on the physical properties of CASB mortar. For this purpose, a flow test and colour evaluation was carried out on white Portland cement paste and mortar mixed with CASB by changing the proportion of RPP. RPP modifies the mechanical properties of the mortar by forming a polymer film in the cementitious matrix. The film prevents the transport of soluble calcium towards the surface and decreases efflorescence. As a result, the colour appearance of CASB mortar improved with increasing RPP content.

Control of intracranial disease is associated with improved survival in patients with brain metastasis from hepatocellular carcinoma.

BACKGROUND: Brain metastasis is a rare event in patients with hepatocellular carcinoma (HCC). This retrospective study aimed to identify the prognostic factors and determine the outcomes of patients with brain metastases from HCC. METHODS: About 86 patients with brain metastases (0.6%) from HCC were identified from two institutions; of them, 32 underwent tumor-removing surgery or stereotactic radiosurgery (SRS) with or without adjuvant whole brain radiotherapy (WBRT) (group 1), 30 had WBRT alone (group 2), and 24 received conservative treatment (group 3). Estimates for overall survival (OS) after brain metastases were determined, and clinical prognostic factors were identified. RESULTS: The median OS after development of brain metastases was 50 days. About 75 (87.2%) patients had lung metastases at the time of brain metastasis diagnosis. Group 1 showed better OS, followed by group 2 and group 3, sequentially (p < 0.001). Univariate analyses showed that treatment with curative intent (surgery or SRS), Child-Pugh class A, alpha-fetoprotein level < 400 ng/ml, and recursive partitioning analysis classification I or II were associated with improved survival (p < 0.001, 0.002, 0.029, and 0.012, respectively). Multivariate analysis showed that treatment with curative intent and Child-Pugh class A was associated with improved OS (p < 0.001 and 0.009, respectively). CONCLUSION: Although the overall prognosis of patients with brain metastases from HCC is extremely poor, patients actively treated with surgery or radiosurgery have prolonged survival, suggesting that interventions to control intracranial disease are important in these patients.

Posterior Available Space for Uprighting Horizontally Impacted Mandibular Second Molars Using Orthodontic Microimplant Anchorage.

Treatment of horizontally and deeply impacted mandibular molars is challenging for both orthodontists and oral surgeons because of the limited access and anchorage control. We report on two patients who had horizontally and mesially impacted mandibular second molars (MM2s). Both patients were treated by a surgical orthodontic approach, and the crowns of the impacted teeth were brought into the arches by closed forced eruption. Mesially impacted MM2s were uprighted with orthodontic microimplants, inserted in the retromolar area, and then moved into their ideal position. The first patient was in an active growing stage, while the second patient was beyond the active growing stage. Therefore posterior available space (PAS) should be analyzed before treatment of impacted MM2s to prevent periodontal problems after uprighting of impacted teeth. If PAS is not enough for uprighting impacted MM2s, alternative treatment should be considered based on the stage of growth.

Correction to: Palliative external beam radiotherapy for the treatment of tumor bleeding in inoperable advanced gastric cancer.

CORRECTION TO: BMC CANCER (2017) 17:541 DOI: 10.1186/S12885-017-3508-X: In the original version of this article [1], published on 12 August 2017, the affiliations and author contributor details were not correct. In this Correction the incorrect affiliations and author contributor details and correct affiliations and author contributor details are shown.

Risk factors for erlotinib-induced hepatotoxicity: a retrospective follow-up study.

BACKGROUND: Erlotinib is a drug used for the treatment of non-small cell lung cancer (NSCLC) and pancreatic cancer. Severe hepatotoxicity was observed in 4% to 31% of patients receiving erlotinib treatment prompting delay or termination of treatment. Only a few factors related to hepatotoxicity of erlotinib have been reported. No study has investigated the role of concomitant medications and erlotinib-induced hepatotoxicity. The aim of this study was to investigate the association between erlotinib-induced hepatotoxicity and various factors including concomitant medications in patients with NSCLC and pancreatic cancer. METHODS: From January 2014 to June 2017, a retrospective study was conducted in patients with NSCLC and pancreatic cancer, who were treated with erlotinib. Various data were reviewed, including sex, age, body weight, height, body surface area (BSA), underlying disease, Eastern Cooperative Oncology Group (ECOG) Performance Status (PS), smoking history, erlotinib dose, EGFR mutation, and concomitant drugs. RESULTS: The incidence of grade 2 or higher hepatotoxicity in the study group of patients was 17.2%. Multivariate analysis showed a 2.7-fold increase in hepatotoxicity with the concomitant use of CYP3A4 inducers. In NSCLC patients, co-administration of H2-antagonist/PPI increased hepatotoxicity 3.5-fold. Among the demographic factors, liver metastasis and age ≥ 65 years were significant risk factors in all study patients and NSCLC patients, respectively; the attributable risks for liver metastasis and age were 46.3% and 71.8%, respectively. Subgroup analysis using pancreatic cancer patients yielded marginally significant results with CYP3A4 inducers and erlotinib-induced hepatotoxicity. Liver metastasis and CYP3A4 inducers also shortened time to hepatotoxicity 2.1 and 2.3-fold, respectively. CONCLUSIONS: Our study showed that concomitant use of CYP3A4 inducers and H2-antagonist/PPI, liver metastasis, and age ≥ 65 were associated with erlotinib-induced hepatotoxicity. Thus, close monitoring of liver function is recommended, especially in patients using CYP3A4 inducers and anti-acid secreting agents.

Impact of adjuvant treatments on survival in Korean patients with WHO grade II gliomas: KNOG 15-02 and KROG 16-04 intergroup study.

INTRODUCTION: Optimal treatment strategies for low-grade glioma (LGG) remain controversial. We analyzed treatment outcomes and evaluated prognostic factors of adult LGG patients in Korea. METHODS: We reviewed the medical records of 555 patients diagnosed with WHO grade II LGG (astrocytoma 37.8%, oligoastrocytoma 15.3%, and oligodendroglioma 46.8%) at 14 institutions between 2000 and 2010. Primary and secondary endpoints were progression-free survival (PFS) and overall survival (OS). Propensity-score matching (PSM) analyses were performed to correct imbalances in patient/tumor characteristics among adjuvant treatment groups. RESULTS: The median follow-up time was 83.4 months, and the 5-year PFS and OS rates were 52.2% and 83.0%, respectively. Male, older age, poorer performance status, multiple lobe involvement, and astrocytoma histology were associated with poorer survival. Among the treatment factors, gross total resection (GTR) was associated with better PFS and OS, and adjuvant chemotherapy with improved PFS. Interestingly, adjuvant radiotherapy (RT) did not improve PFS; rather, it was related with poorer OS. Regarding patient/tumor characteristics, the RT group had poorer characteristics than the non-RT group. After PSM, we detected a tendency for improved PFS in the matched RT group, and no significant difference in OS compared with the matched non-RT group. CONCLUSIONS: The achievement of GTR is important to improve survival in LGG patients. Adjuvant chemotherapy may enhance PFS, but adjuvant RT did not improve survival outcomes. After PSM, we observed potential impacts of adjuvant RT on PFS. Our results may reflect real-world practice and consequently may help to optimize treatment strategies for LGG.

Multi-institutional study of treatment patterns in Korean patients with WHO grade II gliomas: KNOG 15-02 and KROG 16-04 intergroup study.

INTRODUCTION: We performed this study to identify the treatment patterns of patients with low-grade gliomas (LGG) in Korea. METHODS: A total of 555 patients diagnosed as WHO grade II gliomas between 2000 and 2010 at 14 Korean institutions were included. The patients were divided into four adjuvant treatment groups: adjuvant fractionated radiotherapy (RT, N = 204), adjuvant chemotherapy (N = 20), adjuvant fractionated RT and chemotherapy (N = 65), and non-adjuvant treatment (N = 266) groups. We examined differences among the groups and validated patient/tumor characteristics associated with the adjuvant treatments. RESULTS: Astrocytoma was diagnosed in 210 patients (38%), oligoastrocytoma in 85 patients (15%), and oligodendroglioma in 260 patients (47%). Gross total resection was performed in 200 patients (36%), subtotal resection in 153 (28%), partial resection in 71 patients (13%), and biopsy in 131 patients (24%). RT was most commonly applied as an adjuvant treatment. The use of chemotherapy with or without RT decreased after 2008 (from 38 to 4%). The major chemotherapeutic regimen was procarbazine, lomustine, and vincristine (PCV); however, the proportion of temozolomide increased since 2005 (up to 69%). Patient/tumor characteristics related with RT were male gender, non-seizure, multiple lobes involvement, and non-gross total resection. Chemotherapy was associated with non-gross total resection and non-astrocytoma. CONCLUSIONS: A preference for RT and increased use of temozolomide was evident in the treatment pattern of LGG. The extent of resection was associated with a decision to perform RT and chemotherapy. To establish a robust guideline for LGG, further studies including molecular information are needed.

Modeling of Carbon Mortar Color Expression Using Artificial Neural Network.

Colored concrete uses pigments and white Portland cement (WPC) to perform decorative functions together with structural function. Pigments are used in permanent coloring of concrete with colors different from the natural color of the cement or the aggregates with mixing WPC. In this study, an artificial neural networks study was carried out to predict the color evaluation of black mortar using pigment and carbon black. A data set of a laboratory work, in which a total of 9 mortars were produced, was utilized in the Artificial Neural Networks (ANNs) study. The mortar mixture parameters were nine different pigment and carbon black ratios. Each mortar was measured at ten locations on the surface and averaged. Color can be evaluated by measurements of tristimulus values L* , a* and b* , represented in the chromatic space CIELAB. The L* value is a measure of luminosity (0 darkness), from completely opaque (0) to completely transparent (100); a* is a measure of redness (-a* greenness) and b* of yellowness (-b* blueness). ANN model is constructed, trained and tested using these data. The data used in the ANN model are arranged in a format of three input parameters that cover the pigment, carbon black and WPC and, an output parameter which is the color parameters of the black colored mortar. The results showed that ANN can be an alternative approach for the predicting the color parameters using mortar ingredients as input parameters.

Efficacy and safety of compound tri-metal stent placement for malignant perihilar biliary obstruction.

BACKGROUND: Despite many attempts to improve the patency rate of biliary stents in patients with inoperable perihilar cholangiocarcinomas, the longevity of these stents has not been satisfactory. The purpose of the present study is to report technical outcomes and clinical efficacy of the placement of compound tri-metal stent in patients with malignant perihilar biliary obstruction. MATERIALS AND METHODS: Retrospective analysis was performed of the medical records of 26 consecutive patients with inoperable malignant perihilar biliary obstruction who underwent compound tri-metal stent placement through a percutaneous transhepatic biliary drainage tube from January 2012 to April 2017. RESULTS: Placement of the compound tri-metal stent was successfully completed in all 26 patients (technical success, 100%). There was neither procedure-related mortality nor 30-day mortality. None of these patients underwent additional metallic stent placement within 60 days secondary to recurrent cholangitis or stent occlusion. Successful drainage was achieved in 25 (96.2%) of 26 patients who received a compound tri-metal stent. Patients treated with compound tri-metal stent placement had a median stent patency of 145 days (range, 24-426 weeks) and a median survival time of 188 days (range, 37-1732 days). CONCLUSIONS: Placement of compound tri-metal stent in patients with malignant perihilar biliary obstruction may offer a safe and effective alternate technique to improve biliary drainage and stent patency.

Palliative external beam radiotherapy for the treatment of tumor bleeding in inoperable advanced gastric cancer.

BACKGROUND: To assess the outcomes and prognostic factors associated with palliative external beam radiotherapy (EBRT), administered to patients with advanced gastric cancer. METHODS: Forty-two patients with bleeding gastric tumors that received EBRT for palliation were analyzed. The response to EBRT was assessed by the palliation of tumor bleeding. Patients were classified as either responders, or non-responders to EBRT. The prognostic utility of clinical and dosimetric variables was examined in a multivariate logistic regression model. The optimal dose cutoff to classify the two groups was determined with receiver operating characteristic analysis. RESULTS: The palliation of gastric tumor bleeding after EBRT was achieved in 29 patients (69.0%). The time to resolve tumor bleeding ranged from 1 to 84 days (median, 15 days). The median duration of palliation was 14.9 weeks. The median EBRT dose was 40 Gy in responders vs. 21 Gy in non-responders, with the difference being significant (p < 0.001). The biologically effective dose (using α/ß = 10, BED10) for responders was significantly higher than the BED10 for non-responders (median 48 Gy vs. 26.4 Gy, p < 0.001), and the optimal cut off value to separate the two groups was 36 Gy (p < 0.001). The absence of distant metastasis and the use of concurrent chemotherapy generally showed a better EBRT response (p = 0.079 and p = 0.079, respectively). In the multivariate analysis, BED10 ≥ 36 Gy was the most significant factor associated with EBRT response (p = 0.001). Overall survival (OS) and re-bleeding-free survival was median 12.6 weeks and 14.9 weeks. The responders to EBRT showed superior OS (16.6 vs. 5.1 months, p < 0.001). Neither acute nor chronic toxicities of grade 3 or higher were observed. CONCLUSIONS: EBRT is an effective method for treating tumor bleeding in advanced gastric cancer, and does not induce severe toxicity.

Radiotherapeutic strategies for hepatocellular carcinoma with portal vein tumour thrombosis in a hepatitis B endemic area.

BACKGROUND & AIMS: This nationwide, multicenter study investigated treatment outcomes as well as the optimal radiotherapeutic strategy in patients with hepatocellular carcinoma (HCC) and portal vein tumour thrombosis (PVTT). METHODS: We retrospectively reviewed the records of 985 patients who received radiotherapy (RT) for PVTT. The median equivalent RT dose was 48.75 Gy. Combined treatment, defined as liver-directed treatments performed within a month of RT, was administered to 657 patients (66.7%). The PVTT and primary tumour were irradiated in 413 patients (41.9%), and PVTT only was targeted in 572 patients (58.1%). RESULTS: The response rate of the PVTT was 51.8%, and RT responders had a significantly longer survival than non-responders (15.2 vs. 6.9 months). Equivalent RT dose and combined treatment predicted response of PVTT. The median overall survival (OS) was 10.2 months. Multivariate analysis revealed the equivalent RT dose ˃45 Gy and combined treatment as significant positive factors for OS. In the propensity score matching analysis, the combined treatment group had better OS than the no combined treatment group, whereas the OS of the PVTT + primary tumour group did not differ significantly from that of the PVTT only group. CONCLUSION: The equivalent RT dose ˃45 Gy, given in combination with other treatments, provided better PVTT control and OS. The optimal RT volume is suggested for either PVTT + primary or PVTT only. Taken together, multimodal treatment with equivalent RT dose higher than 45 Gy is recommended for patients with HCC and PVTT.

Interobserver variability in gross tumor volume delineation for hepatocellular carcinoma : Results of Korean Radiation Oncology Group 1207 study.

PURPOSE: There has been increasing use of external beam radiotherapy for localized treatment of hepatocellular carcinoma (HCC) with both palliative and curative intent. Quality control of target delineation in primary HCC is essential to deliver adequate doses of radiation to the primary tumor while preserving adjacent healthy organs. We analyzed interobserver variability in gross tumor volume (GTV) delineation for HCC. PATIENTS AND METHODS: Twelve radiation oncologists specializing in liver malignancy participated in a multi-institutional contouring dummy-run study of nine HCC cases and independently delineated GTV on the same set of provided computed tomography images. Quantitative analysis was performed using an expectation maximization algorithm for simultaneous truth and performance level estimation (STAPLE) with kappa statistics calculating agreement between physicians. To quantify the interobserver variability of GTV delineations, the ratio of the actual delineated volume to the estimated consensus volume (STAPLE), the ratio of the common and encompassing volumes, and the coefficient of variation were calculated. RESULTS: The median kappa agreement level was 0.71 (range 0.28-0.86). The ratio of the actual delineated volume to the estimated consensus volume ranged from 0.19 to 1.93 (median 0.94) for all cases. The ratio of the common and encompassing volumes ranged from 0.001 to 0.56 (median 0.25). The coefficient of variation for GTV delineation ranged from 8 to 57 % (median 26 %). CONCLUSION: The interobserver variability in target delineation of HCC GTV in this study is noteworthy. Multi-institution studies involving radiotherapy for HCC require appropriate quality assurance programs for target delineation.

Diffusion-weighted imaging: Apparent diffusion coefficient histogram analysis for detecting pathologic complete response to chemoradiotherapy in locally advanced rectal cancer.

PURPOSE: To investigate the usefulness of apparent diffusion coefficient (ADC) values derived from histogram analysis of the whole rectal cancer as a quantitative parameter to evaluate pathologic complete response (pCR) on preoperative magnetic resonance imaging (MRI). MATERIALS AND METHODS: We enrolled a total of 86 consecutive patients who had undergone surgery for rectal cancer after neoadjuvant chemoradiotherapy (CRT) at our institution between July 2012 and November 2014. Two radiologists who were blinded to the final pathological results reviewed post-CRT MRI to evaluate tumor stage. Quantitative image analysis was performed using T2 -weighted and diffusion-weighted images independently by two radiologists using dedicated software that performed histogram analysis to assess the distribution of ADC in the whole tumor. RESULTS: After surgery, 16 patients were confirmed to have achieved pCR (18.6%). All parameters from pre- and post-CRT ADC histogram showed good or excellent agreement between two readers. The minimum, 10th, 25th, 50th, and 75th percentile and mean ADC from post-CRT ADC histogram were significantly higher in the pCR group than in the non-pCR group for both readers. The 25th percentile value from ADC histogram in post-CRT MRI had the best diagnostic performance for detecting pCR, with an area under the receiver operating characteristic curve of 0.796. CONCLUSION: Low percentile values derived from the ADC histogram analysis of rectal cancer on MRI after CRT showed a significant difference between pCR and non-pCR groups, demonstrating the utility of the ADC value as a quantitative and objective marker to evaluate complete pathologic response to preoperative CRT in rectal cancer. J. Magn. Reson. Imaging 2016;44:212-220.

Can serum dynamics of carcinoembryonic antigen level during neoadjuvant chemoradiotherapy in rectal cancer predict tumor response and recurrence? A multi-institutional retrospective study.

PURPOSE: We evaluate whether the change of carcinoembryonic antigen (CEA) level before and after preoperative chemoradiotherapy (CRT) in rectal cancer affects tumor response and recurrence or not. METHODS: We retrospectively analyzed 1447 rectal cancer patients who underwent preoperative CRT followed by curative surgery. All patients received preoperative radiotherapy of 50.4 Gy in 28 fractions with 5-fluorouracil or capecitabine. Total mesorectal excision was performed 4 to 8 weeks after preoperative CRT. CEA levels were checked before and after CRT. Clinical and pathologic factors were analyzed for tumor response and recurrence. RESULTS: Post-CRT CEA level (cutoff value, 2.5 ng/mL) was not a significant factor for tumor response on the multivariate analysis (p = 0.095). Patients were categorized according to the pre- and post-CRT CEA level (group A: pre-CRT CEA ≤5 ng/mL; group B: pre-CRT CEA >5 ng/mL and post-CRT CEA ≤2.5 ng/mL; group C: pre-CRT CEA >5 ng/mL and post-CRT CEA >2.5 ng/mL). The relapse-free survival (RFS) at 5 years was significantly higher in group A than in groups B and C (82.6 vs. 73.7 % vs. 72.2 %, p < 0.001). The overall survival (OS) at 5 years was significantly higher in group A than in groups B and C (90.1 vs. 84.4 % vs. 83.4 %, p < 0.001). However, there is no significant difference for RFS and OS between groups B and C (all, p > 0.05). CONCLUSIONS: Decline of elevated CEA level (>5 ng/mL) during preoperative chemoradiotherapy has no significant effect on tumor response and recurrence in rectal cancer.

Total Lesion Glycolysis Using ¹8F-FDG PET/CT as a Prognostic Factor for Locally Advanced Esophageal Cancer.

Standardized uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) have been considered prognostic factors for survival in many cancers. However, their prognostic value for radiotherapy-treated squamous esophageal cancer has not been evaluated. In this study, SUV, MTV, and TLG were measured to predict their prognostic role in overall survival (OS) in 38 esophageal cancer patients who had undergone (18)F-FDG PET/CT before radiotherapy. TLG demonstrated higher sensitivity and specificity for predicting OS than MTV and SUV; and a better OS was observed in patients with low TLG compared to those with high TLG in locally advanced disease (OS, 46.9 months; 95% confidence interval [CI], 33.50-60.26 vs. 25.3 months; 95% CI, 8.37-42.28; P=0.003). Multivariate analyses in these patients determined that TLG and the use of combination chemotherapy were the independent prognostic factors for OS (hazard ratio [HR], 7.12; 95% CI, 2.038-24.857; P=0.002 and HR, 6.76; 95% CI, 2.149-21.248; P=0.001, respectively). These results suggest that TLG is an independent prognostic factor for OS and a better predictor of survival than MTV and SUV in patients with locally advanced esophageal cancer treated with radiotherapy.

Forced eruption of impacted maxillary central incisors with severely dilacerated roots.

Treatment of impacted dilacerated incisors is challenging for clinicians because of the prominent position of the teeth and the abnormality of their roots. We report on 2 patients who had horizontally upward impacted and severely dilacerated maxillary central incisors. The first patient's root perforated the labial plate without significant resorption, and the second patient's root was resorbed. Both patients were treated by a surgical-orthodontic approach, and the crowns of the impacted teeth were brought into the arches by closed forced eruption. Therefore, if impacted teeth have dilacerated roots, patients should be told of the possibility of root resorption.